Furnace-door.



G. DE GRAHL.

FURNAGE DOOR.

APPLICATION FILED 00T. 17, 1908.

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GUSTAV DE GRAHL, OF WILMERSDORF, NEAR BERLIN, GERMANY.

FURNACE-DOOR.

Specoaton of Letters Patent.

Patented Dee, 7, LQQ.

Application filed Gotober 1'?, 1908. SeriaI No. 458,290.

To @il whom it may concern:

Be it known that I, GUsTAv DE GRM-IL, a subject of the German Emperor,and residing at Wilmersdorf, near Berlin, Germany, have invented certainnew and useful Iniprovemeuts in Furnace-Doors, of which the following isa specification.

iviy invention relates to boiler furnaces and a primary obi ect is toprovide improvements in and relating to the doors thereof.

Une illustrative embodimentof my invention is represented in theaccompanying drawing', in which,

Figure l shows the device in front elevation, whereas Ifigs. 3, and tareside elevations partly in section, respectively showing the door ciosedat the moment when the door begii'is to open and showing the door open.

Referring to the drawing, #il the furnace door, which is rigidlyconnected with the door shaft Un the door shaft t2 is supportedrevolubly a counter-weight 4-3,said counterweight being provided with ahandle ist. rifhe sector 45, having a nose do, is fastened on the shaftet? by the side of the counterweight 43. On the lug t7 on the upper partof the bearing there is pivoted at 4S the detent lever Lit), which isprovided with the handle 50. rihe bolt 5l is rigidly connected with saiddetent lever -i-Q, said bolt having at a square cross-section. At 52 thepawl is displaceably but not revolubly supported on. the said bolt. Saidpawl is subjected to the action of a spring 5st-, which abnts at one endagainst the abutment 55 on the bolt and presses the pawl 5b continuallyagainst the dctent lever di). t-iaid abutment may be fixed in differentpositions on the bolt l.

ri`hc counter-weight is provided with a projection 5b and the sectorwith the two shoulders 57, 58, the projection being adapted to engagesaid shoulders 57, 58.

Vv'hen the door is to be opened, the counterweight 43 is first movedfrom the position shown in Ifig. 2 into the position shown in Fig. 3,but the door still remains in the closed position. During this movementthe projection 5G of the counterweight 41-3 leaves the shoulder 5S ofthe sector and abuts against the shoulder 57. The counterweight 4?, having` arrived into the position shown in Fig. et, its statical momentwith regard to the shaft 42 facilitates the door being opened so thatthe furnace door can be brought without great expenditure of force intothe open position represented in Fig. 4t. In this position the door isheld by the counterweight t3 which abuts with its projection 5G againstthe shoulder 5t of the sector 415.

Vhen closing the furnace door, the counterweight 4t?) first returns intothe position shown in Fig. 3 and then into the position shown in Fig. Q,the projection 5G of the counterweight r3 leaving the shoulder 57 of thesector L5 and consequently owing to the weight of the furnace door theshoulder 57 of the latter is forced to follow the projection 56 of thecounterweight e3, that is to say, the door returns into its closedposition.

I claim.-

1. In a device of the class described the combination of a furnaceprovided with a door-openiiig, a shaft on the furnace, a door on theshaft for closing the door-opening and able to swing inward, of acounterweight revoluble on said shaft and adapted to balance said door,and a sector having two shoulders fixed on said shaft, saidcounterweight being adapted to coact with and actuatc said sector.

2. In a device of the class described the combination of a furnaceprovided with a door-opening, a shaft on the furnace, a door on theshaft for closing the door-opening and able to swing inward, of acounter-- weight rcvoluble on said shaft and adapted to balance saiddoor, and a sector having two shoulders fixed on said shaft, saidcounterweight having a. projection adapted to coact with and actuatesaid shoulders.

3. In a device of the class described the combination of a furnaceprovided with a door-opening, a shaft on the furnace, a door on theshaft for closing the door-opening and able to swing inward, of acounterweight revoluble on said shaft and adapted to balance `said door,a sector having two shoulders and a nose fixed on said shaft., saidcounterweight having a projection adapted to coact with and actuate saidshoulders, and a detent-lever pivoted on the furnace, said detent-leverhaving a springpressed pawl adapted to engage with said nose.

In testimony whereof, I affix my signature in the presence of twowitnesses.

GUSTAV DE GRAI-IL.

Witnesses FRIEDRICH RoKAI-IR, VVOLDEMAR HAUPT.

